public async Task ComposingMiddlewaresShouldProducesACompositeMiddlewareTask()
{
// Given
var calls = new List <string>();
TaskMiddlewareFunc <string> func = async(str, _) =>
{
calls.Add("Func");
await Task.CompletedTask;
};
TaskMiddleware <string> MakeMiddleware(int count)
{
return(async(str, next, ct) =>
{
calls !.Add("Before" + count);
await next(str, ct);
calls.Add("After" + count);
});
}
var middleware1 = MakeMiddleware(1);
var middleware2 = MakeMiddleware(2);
var middleware3 = MakeMiddleware(3);
var context = "Hello world!";
// When
var middleware = middleware1.Compose(middleware2, middleware3);
await func.Combine(middleware)(context, default);
// Then
calls.Should().Equal("Before1", "Before2", "Before3", "Func", "After3", "After2", "After1");
}
public async Task CombineAMiddlewareAndAFuncShouldReturnAFuncThatCombinesThemTask()
{
// Given
var calls = new List <string>();
TaskMiddlewareFunc <string> func = async(str, _) =>
{
calls.Add($"Func: {str}");
await Task.CompletedTask;
};
TaskMiddleware <string> middleware = async(str, next, ct) =>
{
calls.Add($"Before: {str}");
await next(str, ct);
calls.Add($"After: {str}");
};
var context = "Hello";
// When
await middleware.Combine(func)(context, default);
// Then
calls.Should().Equal("Before: Hello", "Func: Hello", "After: Hello");
}
public static TaskMiddlewareFunc <TContext> Combine <TContext>(
this TaskMiddleware <TContext> middleware,
TaskMiddlewareFunc <TContext> func) =>
(context, ct) => middleware(context, func, ct);
